The present invention relates to digital recording and playback of audio and video streams.
Conventional video cassette recorders (VCRs) record in analog form a video stream received from a video source (e.g., a cable TV cable) onto a tape (e.g., a VHS tape). One way to record a video stream using a conventional VCR is to press a Record button, causing the VCR to begin recording the incoming video stream. The VCR continues recording until the user presses a Stop button. To schedule recording of a video stream (e.g., an upcoming episode of a television show), the user typically indicates the start time, end time, and television channel of the episode. The VCR begins recording the video stream received on the specified channel at the specified start time and stops recording at the specified end time. To play back a video stream recorded with a VCR, the user inserts the tape on which the video stream is recorded into the VCR, positions the tape to the beginning of the recorded video stream using Rewind and Forward buttons, and presses a Play button. Typically, a user must wait until recording has completed before a video stream can be played back.
A user who has access to live video sources such as a television antenna, a cable TV cable, or a Direct Broadcast Satellite (DBS) dish, and to recorded video sources such as a VCR or a camcorder, may connect the outputs of one or more such video sources to a conventional receiver. The user also connects a video display such as a television monitor to the receiver. The user can select which video source is to be output to the television monitor using controls provided by the receiver. For example, to view the output of the VCR (e.g., the contents of a VHS tape) on the television monitor, the user presses a “VCR” button on the receiver. To control the various video sources that are connected to the receiver (e.g., to tune to a particular channel from among the channels received through the television antenna), the user typically uses controls, such as remote controls, associated with the various video sources. Furthermore, each live television source typically has its own set of channels with its own numbering system. Channel numbers used by different live television sources may or may not overlap, and different video sources may or may not associate the same channel number with another channel which contains the same content (e.g., channels which correspond to the same television network).
Some live television providers, such as DBS and some cable systems, provide additional information within the video streams they provide. For example, some systems provide information about upcoming television shows, such as the times at which they are scheduled to air and the channels on which they appear. Some systems display such information using an on-screen menu that displays the times at which upcoming shows will be aired.